Replaceable thimble point dipper tooth



Nov. 3, 1931. .1. OF. CLARK 1,829,851

REPLACEABLE THIMBLE POINT DIPPER TOOTH Filed Nov. 25, 1929 ig/z 02211072 024% Patented Nov." 3, 1 931- UNITED STATES PATENT OFFICE;

JOHN OFALLON CLARK, OF UNIVERSITY CITY, MISSOURI, ASSIGNOR, IBY MESNE AS- MAINE SIGNMENTS, TO AMERICAN MANGANESE STEEL COMPANY, A. CORPORATION OF REPLAGEABLE THIMBLE POINT DIPPER TOOTH Application filed November 25, 1929. Serial No. 409,558

This invention relates to dipper teeth comprising a base fashioned in a known manner to adapt it to be riveted in place upon the digging front of a dipper or similar excavating implement, and a point embodying that portion of the tooth which wears awa more rapidly thanthe base and which, or the sake of economy, is separately formed and replaceably mounted upon the base; andparticularly dipper teeth of the type in which the replaceable point embodies in its construction a socket or cavity which adapts it to fitupon the forward end of the base after the manner of a cap or thimble, andin which the assembling socket comprises. upper and lower divergent walls and a pair of side walls, and the point is secured on the base through means of'an attaching shank extendin rearwardly from one of the divergent wa ls.

'The object'of the present invention is to provide an improved form of attaching or anchoring means for a thimble-shaped point or cap point of the kind described; one in which the anchoring shank will extend from one of the divergent walls of the point and form a part of and assist inwithstanding abrasive force encountered by one face of the. tooth; one in which the attaching means rather than the shear resistance of rivets will act to withstand the weaving tendency of the point under lateral stresses; and one in which attachment and release of the point will be very simple and convenient with the tools available to the operator in the field of use.

Accordingly, the invention proceeds upon the principle of having an anchoring shank or tang extending rearwardly from one of y the divergent walls of the point, and adapted to the'tooth basein a manner to form a por-. tion of the exposed surface of the latter, and

. at the same time having a perforated ofl'set .portion entering a recess inclined inwardly and rearwardly in the member of the base .upon which it laps in a manner to interlock therewith against lateral displacement, and

. at the same time bring the perforation of the [offset portion of the shank into registry with a transverse pin-hole through the base memberrjso that a loc through theparts to resist unintended reking pin may be passed.

enters the. recess in the act of sliding the point upon the base. In the preferred design of the point, the portion of the shank which lies adjacent the point partakes of the full width of the point and constitutes a capping face for that portion of the base upon which the anchoring shank is to be lapped; the width of the shank being, however, reduced rearwardly to meet the offset portion which is laterally restricted sufiiciently to avoid undue encroachment upon the transverse dimensions of those portions of the base memher that constitute the walls of the recess and this reduced rear portion of theshank being countersunk in the base as a further means to stay the point against lateral weaving movement upon the base. I

In the accompanying drawings in which the preferred design of the invention is shown by way of illustration:

Figure 1 is a side elevation of the complete tooth.

Figure 2 is a bottom plan view of the same. Figure 3 is a section in an irregular plane taken on the line 3:v3a2 of Figure 1.

Figure 4 is a detail view in section in a plane indicated by the line 4w4w of Figure perspective view of the point tapered nose 5 which may be sharply reduced in transverse dimensions from the adjoining portion of the'base s2 as to leave an offset 6';

and the point 4 is provided with a receiving socket 7 conforming to the nose and wedging thereon by a rearward longitudinal movement of assembly in a manner to resist diseye'9 having a perforation 10 for receiving a securing pin in a horizontal plane or at. such other substantial angle to the vertical longitudinal plane of the tooth as will enable the tooth to resist displacement of the-shank, and therefore of the tooth. Perforated lug 9 enters an upwardly and rearwardly inclined recess 11 formed in that member of the base 1 upon which it is desired to have the shank 8 lap, and brings the eye 10 of the lug into registry with the pin-hole 12 I extending through that portion of the shank which provides the side walls of the said recess.

That portion of the shank 8 which carries the lug 9 is of reduced width, being defined preferably by converging edges 8a,, and this reduced portion of the shank is counter-sunk within the face of the base upon which the shank laps, through means of the enlarged base portion 11a of the recess 11. In this way a very substantial interlock between the shank and the base is secured in the direction of lateral stresses that "would tend to cause weaving action of the point upon the base; moreover; avoidance of abrupt changes in transverse dimension between the lug 9 and the socket of the tooth reduces liability to breakage.

The forward wall 14 of recess 11.is substantially parallel wiph that one of the converging upper and lower faces of the tapered nose 5 which is remote from the anchoring shank 8, so that perforated lug 9 and the countersunk portion of the shank 8 enter the portions of the recess 11, 11a designed to receive them, by a rearward and inward movement substantially parallel with the said mote face of the tapered nose.

The ends of the pin-hole 12 are enlarged in a direction transverse to the axis of the pin, as suggested at 15, in order to facilitate dieflecting an end .or ends of the pin 13 in a. manher to resist unintentional displacement of the pin, and at the same time to facilitateuse of a wedge beneath the deflected end in straightening up the'pin and bringing it .withm control of the hammer when 'itbecomes necessary to remove the pin and replace the point.

Such, in detail, is the particular design selected for the purpose of illustrating the inverition. In the selected embodiment, the attaching shank 8 is shown as lapping upon the "bottom member 3 of the base; but obviously a design ofthe invention in which this attaching shank with its countersunk portion 8a and offset perforated lug are fitted to the.

walls which embrace the nose laterally, and

an "attaching shank extending rearwardly from one of the converging walls of the socket and constructed with an anchoring lug that extends into the recess of the base; said recess in the base receiving not only the anchoring lug but also a portion of the attaching shank, and the walls of said recess abut- .ting the attaching shank laterally.

2. A tooth as described in clalm 1, in which the recess receives the lug and shank by a movement substantially parallel with that one of the converging surfaces of the nose which is remote from the attaching shank.

3. In an excavating tooth, a base having upper and lower converging faces defining a vertically tapered front end, a point having I a correspondingly tapered socket defined in part by upper and'lower divergent walls. and

an attaching shank in the plane of one of said I divergent walls having its forward portion adjacent its socket, relatively wide, and adapted to overlie one of the converging facesof the base. and having upon its rear portion an integral lug offset inwardly from said attaching shank, of materially less transverse dimension than the tooth and in a vertical longitudinal plane which lies inwardly from the sides of the tooth; said shank being tapered in'width from its portion adjacent the socket to the portion which carries said lug; and said base having a recess positioned to receive said lug.

4. As a new-article of manufacture, a point for di ging teeth comprising a socket portion defined in part by upper and lower converging walls, and an anchoring shank form- .ing a. rearward continuation of one of said a w lls. havinga portlon ad]acent-said socket relatively wide but tapered therefrom toward its rear end and having mounted upon it said rear end an anchoring lug, relatively reduced in width and offset from the plane of saidshank. v v

5. A tooth point as described in claim 4 in which the anchoring lug has a forward faceinclined upwardly and rearwardl in the same general direction as that one o the converging walls of the socket which is remote from the anchoring lug.

6. As a new article of manufacture, a tooth point having upper and lower converging walls defining two faces'of a socket, with an anchoring shank forming a rearward continuation of one of said walls and terminating in an anchoring lug offset from the plane of said shank; saidshank havinglaterally presented faces converging rearwardly toward said lug and providing surfaces through which it is adapted to abut against confining faces on a tooth base.

this 8th day of- November, 1929.

Signed at St. Louis, Missouri,

- JOHN OFALLON CLARK. 

